Thursday, December 8, 2022

A colder and snowier trend has re-emerged in the period leading up to the holiday as we enter a more wintry weather pattern

No warmer trend in this update. I don't particularly enjoy playing that game in the winter and we appear to be done with it for the time being. Additionally, and most importantly, the snow forecast has improved. I wouldn't bet on seeing the the 40 inches of snow yesterday evenings American model advertised over the next two weeks, but when you take that model and the just released European model and incorporate all of it into your possibility spectrum, the potential results improve dramatically. Lets discuss. 

We have a near term (next 5 day) colder trend and one that was needed. There's a small amount of snow to go with that, which, given the current state of the bare ground is very welcome if only for aesthetics.  Friday and Saturday are both bluebird days and sub-freezing across the skiable northern Vermont high country. A subtle jet stream impulse will be crossing the southern Great Lakes region on Saturday as we continue to bask in our December sunshine. It will ultimately energize a new low pressure center in western Pennsylvania and that feature will transition offshore Sunday evening. There is an increasing likelihood that a corridor of moisture will impact some or all of Vermont for several hours and thus bring a small accumulation of snow to the barren ground. We have to start somewhere ! 

In addition to any snow Sunday night, there is a small pocket of chillier temperatures that will get flushed into New England once this storm passes. This allows the first three days of next week to appear colder in the forecast and certainly below freezing across the high country with teens dominating the overnights and 20's during the day. A persistent wind on both Monday and Tuesday will bring wind chill temps below zero as well. Moisture could sneak its way southward from the maritime regions of Canada during this time frame as well but current indications are that this stays east of us. 

The big question next week relates to the storm with a potential impact on Thursday and Friday. I mentioned on twitter that there remains a lot of potential with this sucker. The temperature situation remains tenuous but has moved in our favor a bit on 2 major cycles of model runs. Most importantly, the pattern is there for this to evolve into a big snow producer. There is just a massive pull of jet stream energy with this storm as it matures in the central United States. Normally, the track of such a storm would suck warm air and rain into the region late in the week, but with the downstream jet stream block in place it changes the equation quite significantly. I wish I could lock the just released European model into our forecast but too much could still change. That scenario would have some mixed precipitation change to wet and eventually a more powdery mountain snow that could persist through early Saturday yielding well  over a foot of snow above 2000 feet. A cold rain remains possible however as does a bunch of other outcomes in between. I can say with confidence that temperatures next week won't even closely resemble the disastrous outcome this week. 

Talk of more substantial amounts of colder air has again gained steam in the last few days for the period around the winter solstice and continuing through Christmas. As we approach that time frame the consensus has moved toward a pattern dominated by a downstream block to a pattern dominated more by a upstream block positioned over Alaska. This upstream block is a much more effective mechanism for arctic air delivery in general. Still though, I continue to see obstacles bringing the core of bitterly cold air, bottled up over much of eastern Russia across the pole and into North America and I would favor a forecast with chilly (sub-freezing) but not bitterly cold temperatures. That said, I continue to love the pattern for storm potential. The negative EPO or tamed Pacific jet stream sets up beautifully for additional snow producing storms in a very critical point in the ski season. There is no guarantee the stars align, but the odds are better this year than any other Xmas holiday period I've seen this past decade.

No comments: